Only a second or two passed between the first and second jolt, he said. “The first jolt was more substantial,” he said. “It was bigger.”

“It’s the strongest jolt I’ve ever felt, and I’ve been in the same town for 41 years,” he said.

His 16-year-old son “rode it out like a pro,” he said, but his daughters were “terrified.”

“They were screaming,” he said. “They were absolutely hysterical. I spent a sleepless night hunkering down with the family.”

Sebourn said he spent much of the night talking with the city’s department heads and officials at the emergency command center to get an assessment of the damage. At least two houses and 20 units of an apartment complex have been red-tagged, displacing dozens of people.

On Saturday morning, Sebourn toured the house of a constituent in the 2900 block of Juanita Place on the north end of town that was red-tagged because of structural damage from the quake.

There was a visible crack in the exterior of the two-story house.

“I’m just scared because the house is red-tagged,” said the owner, who did not want to be identified. She said some walls in the house were also cracked.

Juan Rodriguez, who lives next door, said a water main had burst in front of the home.

Rodriguez said he and his family had just returned from dinner when the quake hit.

"It just started to go. It was a good one," he said. "We haven't had one of those in a while."

The shaking was so strong that his SUV started to sway back and forth, he said. Inside the home several bottles and picture frames crashed to the floor.

The family of four was unnerved when the aftershocks kept coming, he said.

"We probably got three or four hours of sleep," he said.

The first of a swarm of earthquakes hit on the border of La Habra and Brea shortly after 8 p.m. Friday with a 3.6 temblor. At 9:09 p.m., the 5.1 shock hit, followed by at least two more aftershocks in the magnitude-3 range in the next half hour.

The 5.1 quake was relatively shallow, which "means the shaking is very concentrated in a small area," Caltech seismologist Egill Hauksson said Friday night. Hauksson said the quake sequence was unusual in that the 5.1 quake was preceded by the weaker foreshock.

U.S. Geological Survey seismologist Lucy Jones said there was a 5% chance that Friday's quake was a foreshock of a larger temblor.

"There could be even a larger earthquake in the next few hours or the next few days," Jones said during a media briefing at Caltech.